Nephew of Lorenzo de’ Medici. First cousin of PopeLeo X. Cardinal in 1513. As archbishop of Florence, Italy he was noted as a reformer. Chief supporter and adviser of Adrian in his attempts to reform the church. Proved unaware of the menace of Lutheranism to the Church, and lost the opening battles against the Reformation for the hearts of the people.

Relations with Holy Roman Emperor Charles V were strained as Clement allied with Francis I of France in the League of Cognac in 1526. Imperial troops attacked Rome in 1527, sacked the city, and held the popehostage. Peace was re-established in 1529, and Clement crowned Charles emperor.

1527 saw the start of KingHenry VIII‘s struggle with the Church to obtain a divorce. Clement’s reaction has been called vacillating, but later canon lawyers maintain that, whether he was influenced by Charles V or not, Clement followed the only course possible on legal grounds.